title: Finite-field implementation of NMR chemical shieldings for molecules: direct and converse gauge-including projector-augmented-wave methods.
abstract: Two finite-field implementations for the calculation of chemical shieldings of molecular systems using a plane-wave basis set and the Gauge-Including Projector-Augmented-Wave method are presented. The direct approach mimics the nuclear magnetic resonance experiment in that it puts the molecule in a uniform magnetic field and obtains shieldings from the current response. The other is based on the recently introduced "converse method" [T. Thonhauser, D. Ceresoli, A. A. Mostofi et al., J. Chem. Phys. 131, 101101 (2009)]. In both methods two-center contributions to the shieldings can be included via a numerically simple augmentation construction. Results obtained with both methods are discussed as well as (dis)similarities in their behaviors.
authors.affiliation: Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands.
authors.forename: Filipe
authors.initials: F
authors.lastname: Vasconcelos
authors.forename: Gilles A
authors.initials: GA
authors.lastname: de Wijs
authors.forename: Remco W A
authors.initials: RW
authors.lastname: Havenith
authors.forename: Martijn
authors.initials: M
authors.lastname: Marsman
authors.forename: Georg
authors.initials: G
authors.lastname: Kresse